CN114649786A

CN114649786A - Wall bushing for a switchgear and switchgear

Info

Publication number: CN114649786A
Application number: CN202210315817.2A
Authority: CN
Inventors: 翟保安; 邱正平; 崔树山
Original assignee: Siemens Switchgear Ltd
Current assignee: Siemens Switchgear Ltd
Priority date: 2022-03-29
Filing date: 2022-03-29
Publication date: 2022-06-21

Abstract

The invention provides a wall bushing for a switchgear and a switchgear, the wall bushing for a switchgear comprising: the radial umbrella skirt (1) comprises a plurality of umbrella leaves (11) which are mutually sleeved, each umbrella leaf (11) is cylindrical and coaxially arranged, the diameter of each umbrella leaf (11) is sequentially reduced from outside to inside, and a connecting part (12) is arranged between every two adjacent umbrella leaves (11); the radial umbrella skirt comprises a disc body (2), wherein the disc body (2) is positioned inside the radial umbrella skirt (1), the disc body (2) is provided with a bus hole (21), and a bus can pass through the radial umbrella skirt (1) through the bus hole (21).

Description

Wall bushing for a switchgear assembly and switchgear assembly

Technical Field

The invention relates to the field of switch equipment, in particular to a wall bushing for switch equipment and the switch equipment.

Background

Switchgear is an important component in electrical power systems. In practical application, a plurality of switch devices may be required to be combined together, and two switch devices are required to be connected together through a wall bushing with an insulated outer surface.

In the prior art, the wall bushing comprises an axial shed, the length of which in the axial direction needs to be long enough to provide a sufficient creepage distance. But if the length of the wall bushing is too long, the distribution of other components inside the switchgear is affected.

Disclosure of Invention

In view of the above, the present invention proposes a wall bushing for a switchgear, comprising:

a radial full skirt, radial full skirt includes that the several overlaps the umbrella page or leaf of establishing each other, and every umbrella page or leaf is tube-shape and coaxial setting, each the diameter of umbrella page or leaf reduces from outside to inside in proper order, has a connecting portion between two adjacent umbrella pages or leaves.

The disc body is positioned inside the radial umbrella skirt and provided with a bus hole, and a bus can pass through the radial umbrella skirt through the bus hole.

According to the wall bushing, the radial umbrella skirt is arranged, so that the creepage direction is close to the radial direction of the wall bushing, the length of the wall bushing in the axial direction can be reduced, and other parts in the switch device are prevented from being influenced as much as possible.

According to the wall bushing as described above, optionally, the lengths of the umbrella leaves increase from outside to inside in sequence. The end part of the umbrella page is arranged in a ladder shape, so that the creepage capacity can be favorably reduced, and a better insulation effect is achieved.

According to the wall bushing as described above, optionally, each flap has the same plane of symmetry, and the axis of the flap is perpendicular to the plane of symmetry. Therefore, the lengths of the umbrella leaves in the switch device and outside the switch device are consistent, materials are convenient to manage, and the umbrella leaves are convenient to install.

A wall bushing as described above, optionally further comprising:

a first metallic shield ring disposed about the axis of said leaf and covered by said radial shed;

and the second metal shielding ring is sleeved outside the first metal shielding ring and covered by the radial umbrella skirt.

The two shielding rings can play a role in shielding an electric field, and the insulating property of the wall bushing is enhanced.

According to the wall bushing, optionally, the first metal shielding ring and the second metal shielding ring are both net-shaped, and net edges of the first metal shielding ring and the second metal shielding ring are curled. The weight of the two metal shielding rings can be reduced by adopting the net shape, and the net edges of the metal shielding rings can be curled outwards, so that the surface of the light ring is formed, and the point discharge can be reduced.

According to the wall bushing as described above, optionally, the first metal shielding ring is used for connecting with the bus bar, and the second metal shielding ring is used for grounding. An even electric field can be formed between the first metal shielding ring and the second metal shielding ring, and the effect of voltage balancing is achieved.

According to the wall bushing as described above, optionally, the first metallic shield ring is located in an innermost flap of the radial shed. Therefore, the first metal shielding ring can be close to the bus and further close to the high-voltage electric field, and the high-voltage electric field can be effectively shielded.

According to the wall bushing as described above, optionally, the second metallic shield ring is located in the middle of a positioning plate perpendicular to the axis of the leaf, at least a portion of the positioning plate being located outside the radial shed, the portion of the positioning plate located outside the radial shed being covered by a layer of insulating material. The wall bushing is convenient to fix on the cabinet body of the switch cabinet.

According to the wall bushing as described above, optionally, the positioning plate is a metal plate.

The invention also provides a switchgear comprising a wall bushing as described in any of the above for a switchgear.

Drawings

The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail preferred embodiments thereof with reference to the attached drawings in which:

fig. 1 is a schematic structural view of a wall bushing according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of the wall bushing of fig. 1.

Fig. 3 is another schematic cross-sectional view of the wall bushing of fig. 1.

Fig. 4 is a schematic structural diagram of a first metallic shielding ring and a second metallic shielding ring according to an embodiment of the present invention.

Fig. 5 is a front view of the wall bushing of fig. 1.

Wherein the reference numbers are as follows:

1-radial umbrella skirt

11-umbrella leaf

111-axis

12-connecting part

13-first Metal Shielding Ring

14-second Metal Shielding Ring

15-locating plate

151-second metal threaded insert

16-insulating material layer

2-dish body

21-bus bar hole

22-first metal threaded insert

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail by referring to the following examples.

The invention provides a wall bushing for a switchgear, which can be arranged on the outer wall of the switchgear, wherein one part of the wall bushing extends into the interior of a cabinet body of the switchgear, and the other part of the wall bushing is positioned outside the cabinet body.

Fig. 1 is a schematic structural view of a wall bushing according to the present invention. As shown in fig. 2 and 3, a cross-sectional view of the wall bushing of fig. 1 is shown. Fig. 4 is a schematic structural diagram of a first metal shielding ring and a second metal shielding ring in a wall bushing. As shown in fig. 5, is a front view of the wall bushing of fig. 1.

The wall bushing comprises a radial umbrella skirt 1 and a disc body 2, wherein the disc body 2 is positioned inside the radial umbrella skirt 1.

The radial umbrella skirt 1 comprises a plurality of umbrella leaves 11 which are mutually sleeved, each umbrella leaf 11 is cylindrical and coaxially arranged, the diameter of each umbrella leaf 11 is reduced from outside to inside in sequence, and a connecting part 12 is arranged between every two adjacent umbrella leaves 11. Fig. 1 to 3 show a case of 3 umbrella leaves 11, and the number of the umbrella leaves 11 can be specifically set according to actual needs, for example, 4, 5 or more. The radial shed 1 is made entirely of an insulating material, such as resin. The radial skirt 1 indicates that the direction of creepage is not along the axial direction of the blades 11, but is close to the radial direction of the blades 11. "radial" is used herein with respect to "axial". As can be seen from fig. 1 to 3, the louver 11 with the largest diameter is located at the outermost side, the louver 11 with the smallest diameter is located at the innermost side, so as to achieve mutual sleeving between the louvers 11, and two adjacent louvers 11 are connected by a connecting portion 12, wherein the material of the connecting portion 12 may be the same as the material of the louvers 11. As an exemplary illustration, the flaps 11 and the connecting portions 12 of the radial skirt 1 may be integrally cast. The creepage direction of the wall bushing is radial, so that the creepage distance does not need to be considered any more in the length in the axis direction, and the length of the wall bushing in the axis direction is shortened.

The tray body 2 may be fixed on an inner wall of the radial umbrella skirt 1, and the tray body 2 has a bus bar hole 21, through which a bus bar (not shown) can pass through the radial umbrella skirt 1. The bus bar is, for example, a copper bar. As an example, the plate 2 is a circular plate, the material of which may be conformed to the radial shed 1, for example it may be integrally formed with the radial shed 1, for example by a casting process. The disc 2 may be perpendicular to the axis 111 of the radial shed 1, for example the radial shed 1 may be symmetrically distributed about the plane in which the disc 2 lies. As shown in fig. 5, the size and shape of the bus holes 21 on the tray body 2 can be adjusted by different molds to fit switching devices of different current levels. In addition, the bus bar holes 21 on the tray body 2 may also be provided with a plurality of bus bars for passing through, and may be specifically arranged according to actual needs.

According to the wall bushing, the radial umbrella skirt 1 is arranged, so that the creepage direction is close to the radial direction of the wall bushing, the length of the wall bushing in the axis 111 direction can be reduced, and other parts in the switch device are prevented from being influenced as much as possible.

Optionally, the length of the flaps 11 of the wall bushing increases from the outside to the inside. The length here refers to the length of the flap 11 in the direction of the axis 111. As an example, as shown in fig. 1 and 2, the length of the outermost flap 11 is smaller than that of the middle flap 11, the length of the middle flap 11 is smaller than that of the innermost flap 11, and the end portions of the flaps 11 are arranged in a step shape, which can be beneficial to reducing creepage capacity and achieve better insulation effect. Furthermore, as can be seen from fig. 2, the creepage direction of the wall bushing is the direction D indicated by the arrow, i.e. the direction in which the tip portion of each louver 11 extends along the line formed by the connection of the tip portions, and the creepage direction D is not along the axis 111 of the louver 11, but is close to the radial direction of the louver 11. If the lengths of the blades 11 of the wall-penetrating sleeves are uniform, the line formed by connecting the tip portions of the blades 11 is the radial direction of the blades 11, and in the case where the lengths of the blades 11 are different as shown in fig. 2, the radial direction of the blades 11 is slightly offset. Note that the line formed by connecting the tip end portions of the respective flaps 11 is not necessarily a straight line, and may be a curved line, but the entire direction is along the creepage direction D.

Alternatively, each flap 11 has one and the same plane of symmetry, the axis 111 of the flap 11 being perpendicular to the plane of symmetry. Therefore, the lengths of the umbrella leaves 11 in the switch device and outside the switch device are consistent, materials are convenient to manage, and the umbrella leaves are convenient to install.

Optionally, the wall bushing also has a first metallic shielding ring 13 and a second metallic shielding ring 14. The first metal shielding ring 13 is disposed around the axis 111 of the flap 11 and covered by the radial umbrella skirt 1, the second metal shielding ring 14 is sleeved outside the first metal shielding ring 13, and the second metal shielding ring 14 is also covered by the radial umbrella skirt 1. As shown in fig. 2 and 3, the first metal shielding ring 13 and the second metal shielding ring 14 are completely covered by the louver 11 to avoid affecting the insulation of the wall bushing. The two shielding rings can play a role in shielding an electric field, and the insulating property of the wall bushing is enhanced. As an exemplary illustration, the first metal shielding ring 13 and the second metal shielding ring 14 are net-shaped, and the net edges of the first metal shielding ring 13 and the second metal shielding ring 14 are curled, so that the weight of the two metal shielding rings can be reduced by using the net-shaped, and the net edges of the metal shielding rings can be curled outwards, so that the surface of the light ring can be formed, and the point discharge can be reduced.

Optionally, a first metallic shielding ring 13 is used for connecting with the bus bar, and a second metallic shielding ring 14 is used for grounding. More specifically, the first metal shielding ring 13 may be connected to the bus bar, so that the first metal shielding ring 13 and the bus bar are equipotential, that is, both are high-voltage potential. The first metal shielding ring 13 can play a certain role in shielding the electric field of the bus. As an exemplary illustration, a first metal threaded insert 22 may be fixed to the tray body 2, for example, by screwing, the first metal threaded insert 22 may be used to connect with the bus bar through a cable, and the first metal shielding ring 13 may contact the first metal threaded insert 22 and thus connect with the bus bar through the first metal threaded insert 22. The second metallic shielding ring 14 can be connected to a grounding component, such as the second metallic threaded insert 151 of the positioning plate 15, so that the voltage thereof is at a low voltage potential relative to the first metallic shielding ring 13, and a uniform electric field can be formed between the first metallic shielding ring 13 and the second metallic shielding ring 14, thereby performing the function of voltage equalization. The metal threaded insert can be in particular a metal insert with an internal thread.

As an exemplary illustration, the second metal shielding ring 14 is located in the middle of a positioning plate 15, the positioning plate 15 is perpendicular to the axis 111 of the umbrella blade 11, at least a portion of the positioning plate 15 is located outside the radial shed 1, and a portion of the positioning plate 15 located outside the radial shed 1 is covered with an insulating material layer 16. As an exemplary illustration, the positioning plate 15 and the second metallic shield ring 14 may be integrally formed. The positioning plate 15 may be a metal plate such that the second metal shielding ring 14 is grounded through the positioning plate 15. As can be seen in fig. 2 and 3, the positioning plate 15 is partially located in the radial shed 1 and partially covered by a layer 16 of insulating material, the layer 16 of insulating material possibly conforming to the material of the radial shed 1, for example the portion 16 of insulating material integral with the radial shed 1. The second metal threaded insert 151 can simultaneously penetrate through the insulating material layer 16 at a corresponding position on the positioning plate 15, so that the wall bushing can be fixed to the switchgear cabinet by means of the positioning plate 15 covered with the insulating material layer 16. Because switchgear's cabinet body is grounded, the bolt stretches into in the second metal thread inserts 151 of locating plate 15, can make the cabinet body and locating plate 15 form the electricity and be connected, and then makes locating plate 15, the equal ground connection of second metal shield ring 14. As an illustrative example, the positioning plate 15 may be located in a plane that is a plane of symmetry of the leaf 11.

Alternatively, the first metal shielding ring 13 may be located in the innermost flap 11 of the radial shed 1, so that the first metal shielding ring 13 can be close to the bus bar and further close to the high-voltage electric field, and the high-voltage electric field can be shielded more effectively.

The invention also provides a switchgear comprising a wall bushing according to any of the embodiments described above.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A wall bushing for switchgear, comprising:

the radial umbrella skirt (1) comprises a plurality of umbrella leaves (11) which are mutually sleeved, each umbrella leaf (11) is cylindrical and coaxially arranged, the diameter of each umbrella leaf (11) is sequentially reduced from outside to inside, and a connecting part (12) is arranged between every two adjacent umbrella leaves (11);

the radial umbrella skirt comprises a disc body (2), wherein the disc body (2) is positioned inside the radial umbrella skirt (1), the disc body (2) is provided with a bus hole (21), and a bus can pass through the radial umbrella skirt (1) through the bus hole (21).

2. A wall bushing according to claim 1, wherein the length of the flaps (11) increases from the outside inwards in sequence.

3. A wall bushing according to claim 1, wherein the louvers (11) have one and the same plane of symmetry, and the axis (111) of the louver (11) is perpendicular to the plane of symmetry.

4. A wall bushing according to any one of claims 1-3, further comprising:

-a first metallic shielding ring (13) arranged around the axis (111) of the leaf (11) and covered by the radial shed (1);

a second metal shielding ring (14) sleeved outside the first metal shielding ring (13), wherein the second metal shielding ring (14) is covered by the radial umbrella skirt (1).

5. A wall bushing according to claim 4, wherein the first metallic shielding ring (13) and the second metallic shielding ring (14) are both net-shaped, and the net edges of the first metallic shielding ring (13) and the second metallic shielding ring (14) are curled.

6. A wall bushing according to claim 4, wherein the first metallic shield ring (13) is adapted to be connected to the busbar and the second metallic shield ring (14) is adapted to be grounded.

7. A wall bushing according to claim 4, characterized in that the first metallic shielding ring (13) is located in the innermost flap (11) of the radial shed (1).

8. A wall bushing according to claim 4, wherein the second metallic shielding ring (14) is located in the middle of a spacer plate (15), the spacer plate (15) being perpendicular to the axis (111) of the leaf (11), at least a portion of the spacer plate (15) being located outside the radial shed (1), the portion of the spacer plate (15) located outside the radial shed (1) being covered by a layer (16) of insulating material.

9. A wall bushing according to claim 8, wherein the spacer plate (15) is a metal plate.

10. Switchgear characterized in that it comprises a wall bushing for a switchgear according to any of claims 1-9.